The Recent Advance of the Ross Ice Shelf Antarctica

Jacobs, Stanley S.; MacAyeal, Douglas R.; Ardai, J. L.

doi:10.1017/s0022143000012181

Cited by 43 publications

(1 citation statement)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ice shelves, the floating extensions of land-based ice, restrain flow of ice into the ocean by generating buttressing from friction with ice-shelf sides or local seafloor highs, and so are important to sea-level change (e.g., Fürst et al 2016). The large Ross Ice Shelf was discovered in 1841 by an expedition commanded by Sir James Clark Ross, and he would still recognize the great ice barrier today, which is in more or less the same position (for small-scale advances and retreats and for maps of key locations, see Jacobs et al 1986 andLazzara et al 1999). Furthermore, Ross would have recognized the barrier for many millennia preceding.…”

Section: Persistence Of Calvingmentioning

confidence: 99%

Iceberg Calving: Regimes and Transitions

Alley

Cuffey

Bassis

et al. 2023

Annual Review of Earth and Planetary Sciences

View full text Add to dashboard Cite

Uncertainty about sea-level rise is dominated by uncertainty about iceberg calving, mass loss from glaciers or ice sheets by fracturing. Review of the rapidly growing calving literature leads to a few overarching hypotheses. Almost all calving occurs near or just downglacier of a location where ice flows into an environment more favorable for calving, so the calving rate is controlled primarily by flow to the ice margin rather than by fracturing. Calving can be classified into five regimes, which tend to be persistent, predictable, and insensitive to small perturbations in flow velocity, ice characteristics, or environmental forcing; these regimes can be studied instrumentally. Sufficiently large perturbations may cause sometimes-rapid transitions between regimes or between calving and noncalving behavior, during which fracturing may control the rate of calving. Regime transitions underlie the largest uncertainties in sea-level rise projections, but with few, important exceptions, have not been observed instrumentally. This is especially true of the most important regime transitions for sea-level rise. Process-based models informed by studies of ongoing calving, and assimilation of deep-time paleoclimatic data, may help reduce uncertainties about regime transitions. Failure to include calving accurately in predictive models could lead to large underestimates of warming-induced sea-level rise. ▪ Iceberg calving, the breakage of ice from glaciers and ice sheets, affects sea level and many other environmental issues. ▪ Modern rates of iceberg calving usually are controlled by the rate of ice flow past restraining points, not by the brittle calving processes. ▪ Calving can be classified into five regimes, which are persistent, predictable, and insensitive to small perturbations. ▪ Transitions between calving regimes are especially important and with warming might cause faster sea-level rise than generally projected. Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 51 is May 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

show abstract

Section: Persistence Of Calvingmentioning

confidence: 99%

Iceberg Calving: Regimes and Transitions

Alley

Cuffey

Bassis

et al. 2023

Annual Review of Earth and Planetary Sciences

View full text Add to dashboard Cite

show abstract

Structural and environmental controls on Antarctic ice shelf rift propagation inferred from satellite monitoring

et al. 2013

View full text Add to dashboard Cite

[1] Iceberg calving from ice shelves accounts for nearly half of the mass loss from the Antarctic Ice Sheet, yet our understanding of this process is limited. The precursor to iceberg calving is large through-cutting fractures, called "rifts," that can propagate for decades after they have initiated until they become iceberg detachment boundaries. To improve our knowledge of rift propagation, we monitored the lengths of 78 rifts in 13 Antarctic ice shelves using satellite imagery from the Moderate Resolution Imaging Spectroradiometer and Multiangle Imaging Spectroradiometer between 2002 and 2012. This data set allowed us to monitor trends in rift propagation over the past decade and test if variation in trends is controlled by variable environmental forcings. We found that 43 of the 78 rifts were dormant, i.e., propagated less than 500 m over the observational interval. We found only seven rifts propagated continuously throughout the decade. An additional eight rifts propagated for at least 2 years prior to arresting and remaining dormant for the rest of the decade, and 13 rifts exhibited isolated sudden bursts of propagation after 2 or more years of dormancy. Twelve of the fifteen active rifts were initiated at the ice shelf fronts, suggesting that front-initiated rifts are more active than across-flow rifts. Although we did not find a link between the observed variability in rift propagation rate and changes in atmospheric temperature or sea ice concentration correlated with, we did find a statistically significant correlation between the arrival of tsunamis and propagation of front-initiated rifts in eight ice shelves. This suggests a connection between ice shelf rift propagation and mechanical ocean interaction that needs to be better understood.Citation: Walker, C. C., J. N. Bassis, H. A. Fricker, and R. J. Czerwinski (2013), Structural and environmental controls on Antarctic ice shelf rift propagation inferred from satellite monitoring,

show abstract

Seismicity within a propagating ice shelf rift: The relationship between icequake locations and ice shelf structure

et al. 2014

View full text Add to dashboard Cite

Iceberg calving is a dominant mass loss mechanism for Antarctic ice shelves, second only to basal melting. An important process involved in calving is the initiation and propagation of through-penetrating fractures called rifts; however, the mechanisms controlling rift propagation remain poorly understood. To investigate the mechanics of ice shelf rifting, we analyzed seismicity associated with a propagating rift tip on the Amery Ice Shelf, using data collected during the austral summers of [2004][2005][2006][2007]. We apply a suite of passive seismological techniques including icequake locations, back projection, and moment tensor inversion. We confirm previous results that show ice shelf rifting is characterized by periods of relative quiescence punctuated by swarms of intense seismicity of 1 to 3 h. Even during periods of quiescence, we find significant deformation around the rift tip. Moment tensors, calculated for a subset of the largest icequakes (M w > À2.0) located near the rift tip, show steeply dipping fault planes, horizontal or shallowly plunging stress orientations, and often have a significant volumetric component. They also reveal that much of the observed seismicity is limited to the upper 50 m of the ice shelf. This suggests a complex system of deformation that involves the propagating rift, the region behind the rift tip, and a system of rift-transverse crevasses. Small-scale variations in the mechanical structure of the ice shelf, especially rift-transverse crevasses and accreted marine ice, play an important role in modulating the rate and location of seismicity associated with the propagating ice shelf rifts.

show abstract

The Recent Advance of the Ross Ice Shelf Antarctica

Cited by 43 publications

References 27 publications

Iceberg Calving: Regimes and Transitions

Iceberg Calving: Regimes and Transitions

Structural and environmental controls on Antarctic ice shelf rift propagation inferred from satellite monitoring

Seismicity within a propagating ice shelf rift: The relationship between icequake locations and ice shelf structure

Contact Info

Product

Resources

About